|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|6465296||1422950||2017||15 صفحه PDF||سفارش دهید||دانلود رایگان|
- We firstly prepare TiO2 nanofiber/activated carbon fiber porous composites.
- TiO2 ultralong nanofibers were constructed by nanocrystals.
- The composites exhibit synergetic adsorption-photocatalytic activities for toluene.
- The adsorption efficiency reaches 98.9% at toluene concentration of <4600Â ppm.
- Activated carbon fibers improve the quantum efficiency of TiO2.
Effective adsorption and photodegradation of volatile organic compounds (VOCs) especially for the high concentrations still remained great challenges. Herein, we firstly fabricated ultralong TiO2 nanofiber/activated carbon fiber (TiNF/ACF) porous composites by deposition of TiNFs within ACF felts. The ultralong TiNFs with diameters of 30-100Â nm and lengths of >200Â Î¼m were originated from the ordered aggregates of nanocrystals along the [1Â 0Â 1] direction. The TiNF/ACF porous composites possessed excellent adsorption property for toluene, and the adsorption performances were fit well with pseudo-second-order kinetics model. Their adsorption efficiency reached 98.9% at the toluene concentration of <4600Â ppm and 85.7% even at the high concentration of 13,800Â ppm. Moreover, the synergetic effect between the TiNFs and ACFs improved remarkably the photodegradation activity of the composites. The ACFs not only increased the quantum efficiency of TiO2 by hindering the recombination of electron-hole pairs, but also enhanced the light adsorption ability by reducing the TiO2 band gap energy (Eg) to 2.99Â eV. At the toluene concentrations of 115Â ppm or 230Â ppm, the photocatalytic time in which toluene degraded into CO2 and H2O was only 5Â h or 13Â h, respectively. The photodegradation kinetics of toluene matched well with the apparent first-order reaction kinetics model at high concentration of 690Â ppm, while that matched well with the semi-empirical power-law expression equation of CO2 desorption at low concentrations of 115Â ppm. Hence, the TiNF/ACF porous composites with excellent adsorption and photocatalytic activities had great application potentials for VOC removal.
Journal: Chemical Engineering Journal - Volume 328, 15 November 2017, Pages 962-976